[0001] The present invention relates to push chairs for children, and particularly to the
type known as baby buggies.
[0002] Traditionally, push chairs for children have been of a perambulator ("pram") type,
consisting of a boat-like gondola supported via a coach-type mounting by two pairs
of relatively large wheels. In recent decades, however, a different type of child's
push chair, commonly known as a baby buggy, has become popular.
[0003] The conventional construction of a baby buggy consists of two A frames linked by
cross struts and having a seat located between them. Each of the two feet of each
A frame has a wheel attached; one of the sloping sides of each A frame is extended
at its upper end to form handle means by which the buggy can be pushed; and one of
the three sides of the A frame (usually the side which extends to the handle) is hinged
so that the buggy can be folded up eg for storage. In some designs of buggy, the two
A frames can also be collapsed together - this is commonly termed an umbrella fold.
[0004] The seat of a buggy can vary widely. In its simplest form, the seat may be little
more than a strip of material (of the type used eg for deck-chairs) held by top and
bottom cross-bars; with a suitable amount of slack, this sags to form a simple but
adequate seat. More elaborate seats are however common, having relatively rigid back
and base parts. Side parts of more or less rigidity may also be provided. Foot-rests
may also be provided.
[0005] It is desirable for the seat to be adjustable, to provide an upright position for
an alert child but to provide a more reclined position when the child is tired or
sleepy; similarly adjustability is also desirable if children of different ages are
to be carried at different times or to allow the same push-chair to be kept in use
as a child grows. A fully flat or cot position is also desirable, to allow a baby
to be carried. The major feature of such adjustment involves changing the angle of
the back of the seal between near upright and near horizontal. Of course, providing
adjustability of the seat must still permit the buggy to be folded up.
[0006] Providing adjustability of the seat must of course still permit the buggy to be folded
up. For a buggy to be foldable, there are fairly severe geometrical constraints on
it, and to satisfy these, the fully folded configuration has to be unique. As a result,
the setting of the seat position is lost when the buggy is folded.
[0007] We have realized that it is nevertheless possible to store the setting of the seat,
so that when the buggy is unfolded, the seat returns to the setting which it had had
before the buggy way folded.
[0008] According to the invention, therefore, there is provided a foldable baby buggy with
an adjustable seat, including seat position setting means settable to store the chosen
seat position and to thereafter return the seat to that position when the buggy is
unfolded.
[0009] The preferred form of the seat position setting means comprises a disc mounted for
independent rotation on a hinge between two bars, with means for locking the position
of the disc relative to one bar and means for limiting the rotation of the other bar
relative to the disc.
[0010] According to a further feature, the invention provides a buggy wherein the seat comprises
a seat back settable to a range of positions between relatively upright and fully
reclined and hinged to a seat base arranged to slide forward substantially horizontally
as the seat back moves to the reclined position.
[0011] Preferably a first point on the seat back and partway thereup is coupled to the frame
of the buggy by coupling means so as to move vertically, a second point on the seat
back partway between the first point and the bottom edge thereof is coupled to the
frame by a hinged bar so as to move diagonally forward and downward, and the seat
base is slidably mounted on the frame to move horizontally.
[0012] Preferably a first point on the seat back and partway thereup is coupled to the frame
of the buggy by coupling means so as to move vertically, a second point on the seat
back partway between the first point and the bottom edge thereof is coupled to the
frame by a hinged bar so as to move diagonally forward and downward, and the seat
base is slidably mounted on the frame to move horizontally.
[0013] Preferably the hinged bar extends upward beyond the seat back to form an X linkage
therewith, an upper horizontal bar is hinged to the top end of that bar, and a vertical
link bar is hinged between the forward ends of the tipper horizontal bar and the seat
base.
[0014] Preferably also the coupling means comprises a bar exending rearward from the seat
back and a further horizontal bar is provided, hinged at one end to the forward end
of the upper horizontal bar and sliding at its back end on the further horizontal
bar.
[0015] It will of course be realized that the terms horizontal and vertical are used only
to indicate rough directions.
[0016] A baby buggy embodying the invention will now be described, by way of example, with
reference to the drawings, in which:
Fig. 1 is a diagrammatic side view of the main structural components of a buggy;
Fig. 2 is a diagrammatic side view of the bar assembly for supporting the seat;
Fig. 3 is a diagrammatic side view of the locking mechanism;
Fig. 4 is a partial diagrammatic top view of the locking mechanism;
Fig. 5 is a partial diagrammatic top view of a modification of the locking mechanism;
Fig. 6 is a partial diagrammatic top view of a modified locking mechanism;
Fig. 7 is a perspective view of the complete buggy in the cot position, and;
Fig. 8 is a perspective view of the complete buggy in the unreclined seating position.
[0017] Fig. 1 is a simplified side view of a basic buggy, showing the A frame. This frame
consists of a front sloping bar 10, a rear sloping bar 11, and a bottom horizontal
bar 12. The front and rear bars 10 and 11 have wheels 13 and 14 attached to their
lower ends, as shown. The front bar 10 is also extended and curved at its upper end
to provide a handle 10A, which may consist of a suitable termination of the bar or
of a cross-bar between the two A frames, which is able to collapse together as the
buggy is folded. As shown, the front sloping bar 10 is also curved at its lower end
to bring the wheel 13 backward somewhat, and the rear sloping bar 11 is curved at
its upper end to bring its junction with the front sloping bar 10 downward somewhat.
[0018] The bars 10-12 are attached to each other by hinged pivots 15-17 as shown. In addition,
the front bar 10 has a lockable hinge 18 located roughly midway between the pivots
15 and 17. This hinge 18 can be locked in the position shown, ie with the bar 10 straight,
holding the A frame rigidly in the configuration shown. It can also be released, allowing
the front bar 10 to fold inward as indicated by arrow 19, to collapse the frame and
allow the buggy to be folded into a compact form for storage. In addition, the cross-bars
and other elements may be lockably hinged so that the buggy can be folded by having
its two A frames pushed together as well as by the folding of the individual A frames.
[0019] The buggy comprises two A frames, one for each side, which are kept apart by cross
struts 70, 71 which is locked out and released to unfold and fold the buggy respectively
by means of a standard "music stand" arrangement 72, as shown in Figs. 7 and 8. In
addition, a seat 20 is mounted between the two A frames, being suitably attached to
the frames and/or cross struts. The simplest form of seat consists of little more
than a strip of flexible cloth, but many more elaborate versions are possible. A padded
and shaped seat supported by rigid members around its upper edges may be used, and
may contain rigid flat elements to give it greater strength and to maintain its shape,
or a substantially rigid plastics moulding may be used, somewhat like a child's car
seat. Also, if the seat contains reasonably rigid members, it will usually be formed
as two portions which are relatively rigid or maintain their shape reasonably well
but are lunged together or otherwise flexibly coupled together so that the seal folds
with the folding of the A frames.
[0020] Fig. 2 is a simplified diagram of the seat structure of the present buggy. The seat
structure consists of two matching bar assemblies, each attached to a respective one
of the two A frames; extending between these two bar assemblies there are seating
members on which a child actually rests. The drawing shows one of the two bar assemblies.
[0021] The bar assembly comprises two main members, a back bar 25 and a base bar 26, which
are hinged together by a hinge 27. A back seating member extends between the back
bars of the two bar assemblies, and a base seating member extends between the base
bars of the two bar assemblies.
[0022] The back bar 25 is coupled to the rear sloping bar 11 of the A frame by a bar 28,
which is hinged to the back bar 25 by a hinge 29 and to the A frame bar 11 by a hinge
30 as shown. The base bar 26 is coupled to the A frame by a slide 24 which allows
the bar 26 to slide. The slide 24 is mounted on the A frame in the region of the hinge
17, and can conveniently be mounted on the bar 12. Further, there is a bar 31, hinged
at 32 on the A frame bar 12, and hinged near its midpoint by a hinge 33 to a point
on the back bar 25 roughly midway between hinges 27 and 29. Hinge 33 is in fact mounted
on the bar 12 but located slightly above the bar, as shown.
[0023] The bar 28 is roughly horizontal, so its pivoting about the hinge 30 results in the
hinge 29 at its other end moving roughly vertically. Hinge 29 is roughly vertically
above hinge 32. The bar 31 and the section of the bar 25 between hinges 27 and 29
therefore form an X linkage. As hinge 29 moves downward, closer to hinge 32, so hinge
27 moves horizontally forward. The forward horizontal movement of hinge 27 slides
the base bar 26 forward through the slide 24. Since hinge 27 moves roughly horizontally,
the base bar 26 remains roughly horizontal.
[0024] The bar assembly as described so far can thus be operated to rotate the back bar
25 from the near-upright position to the near-horizontal, with the base bar 26 remaining
roughly horizontal but sliding forward at the same time. The seat held between the
two bar assemblies is thus movable between the upright and roughly flat positions.
[0025] Returning to the bar 31, the other end of this bar is hinged by a hinge 34 to a bar
35 which extends forward roughly horizontally, and is coupled to the end of the base
bar 26 by a bar 36 hinged to the bars 26 and 35 by hinges 37 and 38. Bars 26 and 35
are roughly the same length. As the seat is moved toward the reclining or flat position,
the X linkage of bars 25 and 31 causes hinge 34 to move forward, so that it remains
roughly above hinge 27. The bar 36 linking the ends of bars 26 and 35 ensures that
bar 35 remains roughly horizontal and moves roughly parallel with bar 26. (As the
seat is moved toward the reclined position, hinge 34 will move downward as well as
moving forward with hinge 27, so the rearward end of bar 35 will in fact tilt slightly
downward at the same time as the bar moves bodily forward.)
[0026] A final bar 39 is hinged to bars 35 and 36 at hinge 38, and extends backward to end
in a slider 40 which slides on the bar 28. This bar may be slightly curved, as shown,
to keep it clear of the bars 28 and 35, and may carry a dependent shield (not shown)
located between the A frame and the bar assembly, to protect and conceal the bar assembly
mechanism (or parts of it).
[0027] When the seat is in the fully upright position, the two bars 25 and 31 of the X frame
are not far from coincident, with hinges 29 and 34 being close to each other and hinges
27 and 32 being close to each other. The A frame and the bar assembly together form,
roughly, two similar parallelograms, one formed by hinges 16, 30, 29, and 32 and the
other formed by hinges 27, 34, 38, and 37. If the A frame is folded up with the seat
in this upright position, these two parallelograms collapse together, with the bars
28, 35, and 39 moving roughly as a unit forward and downward to lie against bars 12
and 26.
[0028] If the bar 26 is allowed to move freely, ie unconstrained by the rest of the bar
assembly, and is rotated clockwise in the slider 24, the hinge 27 at its rear end
will bear against the A frame bar 12 is the bar 26 and limit its rotation. When the
A frame is fully open, the hinge 27 will in fact be in contact with the bar 12 only
if the seat is in the fully upright position. From this position, the folding of the
bar assembly is as described above. If the seat is not in the fully upright position,
however, the hinge 27 will be somewhat above the bar 12. The folding of the bar assembly
will then occur in two stages.
[0029] In the first stage, the parallelogram formed by hinges 16, 30, 29, and 32 will gradually
collapse; the two bars 25 and 31 of the X frame will remain at the same angle to each
other, with the X frame (ie these two bars 25 and 31) rotating bodily anticlockwise.
This movement will move the hinge 27 at the bottom front corner of the X frame downward.
Eventually, this hinge will contact the bar 12. The second stage of the folding then
starts. Since hinge 27 cannot move further downward, it moves backward, sliding along
the bar 12. This causes the bar 25 to rotate faster than the bar 31, so bringing these
two bars toward alignment.
[0030] The first stage of folding is thus different for each different setting of the seat
position, but the second stage is common to all settings. The different settings cause
the assembly to initially follow a set of distinct but parallel first trajectories,
so to speak, with each of these trajectories ending at a different point on the common
second trajectory.
[0031] Unfolding is of course the reverse of folding. More specifically, the bar assembly
will unfold along the common second trajectory, to the fully upright position; the
seat can then be manually adjusted to a desired partially or wholly reclining position.
[0032] The bar assembly must also, of course, include some means for locking it into a desired
position. As discussed below, a convenient place for this mechanism is at the hinge
33. The locking mechanism may be designed to lock the bars 25 and 31 rigidly together,
in which case it will normally of course have to be released to fold the mechanism.
However, in normal circumstances the seat will always tend to move toward the reclining
position. The locking mechanism may therefore alternatively be a ratchet type mechanism
which is settable to prevent the seat from moving further toward the fully reclined
position but allows it to move the other way to the upright position. This allows
the seat to be folded without the locking mechanism having to be released.
[0033] It will of course be realized that the details of the structure can be varied slightly
from those described above. For example, the bar 25 may be slightly curved between
the hinges 27 and 29, with hinge 33 lying slightly rearward of the straight line between
hinges 27 and 29, and hinge 33 may not lie exactly at the midpoint of either or both
the arms of the X frame. Also, the operation has been described above in simplified
and slightly idealized terms.
[0034] Figs. 3 and 4 show the locking mechanism in more detail.
[0035] The back bar 25 of the seat 20 consists of two members 25A and 25B. Member 25A is
a plastics moulding, carrying two projecting mountings 45 and 46 as shown in Fig.
4. (To reduce the complexity of Fig. 3, mounting 46 is not shown in that drawing.)
Member 25B is a tubular shaft (omitted from Fig. 3 to reduce complexity) which is
held in mountings 45 and 46. The shaft 25B has a pin 48 projecting from it through
a slot 47 in the mounting 45. The shaft 25B therefore forms an extension of the member
25B, being held longitudinally thereon. The other end (not shown) of the shaft 25B
may be bent over to form a handle. The shaft 25B may be rotated in its mountings 45
and 46 so that its handle points inward, ie across the body of the buggy, for normal
use but can be rotated to lie flat with the rest of the bar assembly when the buggy
is folded up.
[0036] As shown in Fig. 3, the bar 31 is hinged at 33 with the member 25A. The bar 31 carries
a semicircular element 50 with a plurality of depressions 51 around its edge. A ratchet
pin 52 is mounted on the member 25A, and spring-loaded by a spring 53 (pressing against
a stop 54 on the member 25A). An operating wire (not shown) is coupled to the pin
52 and extends along the shaft 25B to its far end, where it terminates in any convenient
means for pulling it to retract the pin 52, eg a simple cranked lever mounted under
the handle on the end of the shaft 25B. The position of the operating wire adapts
naturally to any turning of the shaft 25B without any significant effect on the pin
52.
[0037] To release the seat for adjustment, the lever 52 is retracted away from the semicircle
50 by means of the operating wire. This frees the bar 31 to rotate on the hinge 33.
The seat is adjusted to a desired position, and the operating wire is then released.
The pin 52 will then enter one of the depressions 51 on the semicircle 50. This locks
the bar 31 and the member 25A together, so that the seat is held in the desired position.
To change the adjustment or to fold the buggy, the pin 52 must of course be retracted.
[0038] Fig. 6 shows a preferred modification of the locking mechanism. The semicircle 50
on the bar 31 has a series of holes close 51' to its edge, and instead of the pin
52 there is a lever 52' mounted on a mounting 56 on the member 25A. The lever 52'
has a peg 55 on one end which will engage with the holes 51' on the semicircle 50.
This engagement is urged by a spring 54'; the engagement is released by pulling on
the operating wire 57.
[0039] Fig. 6 shows a more elaborate form of locking mechanism. In this, the semicircle
50 has been replaced by a full circle or disc 50A which is separate from the bar 31
and mounted for independent rotation on the hinge 33. This disc 50A is spring-urged
by a spring (not shown) for clockwise rotation. The disc carries two pegs 60 which
engage with the bar 31.
[0040] The setting of the seat position can be changed as follows. Assume that the seat
is to be moved to a more upright position. This can be done regardless of the setting
of the disc 50A, since it involves rotating the bar 31 clockwise, away from the pegs
60 on the disc. Once the desired position has been reached, the pin 52 is withdrawn
from the disc 50A. The disc will then rotate clockwise, under its spring loading,
until the pegs 60 contact the bar 31. The pin 52 is then released to engage with a
depression 51 in the disc 50A. If the seat is to be moved to a more reclined position,
the pin 52 must be withdrawn before adjustment can begin; it may be convenient then
to move the seat to the fully reclined position, release the pin 52, and adjust the
seat back up toward the desired position.
[0041] It will of course be realized that this locking mechanism can be applied to one or
both sides of the buggy, and can be applied to any convenient junction of two bars
in the bar assembly or between the bar assembly and the A frame.
[0042] Assume that the seat has been set to a desired position, so that the disc 50A has
been locked in position on the member 25A. The bar 23 is able to rotate clockwise,
but its rotation anti-clockwise will be limited by its coming into contact with the
pegs 60. As described above, to fold the buggy, the bar 31 rotates clockwise relative
to bar 25. The buggy can therefore be folded up regardless of the setting of the disc
60. When the buggy is unfolded, however, the seat will be held at the previously set
position during the unfolding.
[0043] For this, the seat must naturally tend toward the fully reclined position. This can
be ensured by providing suitable spring loading on the bar assembly. For example,
a spring (not shown) can be provided at the hinge 32, tending to force the bar 31
anticlockwise. This will ensure that the rearward end of the bar 26 is held bearing
down against the bar 12 during unfolding, taking the seat along the "fully reclining"
trajectory. When the seat reaches its preset position, it leaves the "fully reclining"
trajectory and follows the trajectory for the set degree of reclining until the buggy
is fully unfolded.
[0044] Fig. 7 shows the compete buggy in the cot mode, with the seat back being arranged
to form the bottom of the cot. This is achieved by the releasing the seat back from
the back bar 25 and allowing it to fall downwardly in Fig. 7 from the back bar 25.
In the cot position the back bar is not quite horizontal but is slightly inclined
and the seat back falls below the back bar 25 in a pivoting action about the hinge
27 with the seat so that the seat back is horizontal and is then the cot base. The
upholstery on the side of the seat back is tailored to extend to form the side of
the cot between the back bar and the seat back/cot base. An additional detachable
hood 80 is added to the front end, that is the seat end, of the cot, to form the complete
pram in this mode.
[0045] Fig. 8 shows the complete buggy in the seating mode with the seat back not inclined.
The seat back may be inclined to a variety of inclinations and the buggy may be folded
in any reclined position or in the cot position. When the buggy is subsequently unfolded
the seat back remains in the previous inclined position, or the cot position, at time
time of folding. This has significant advantages for the user. Existing buggies may
only be folded in the upright position or always return to the upright position when
the buggy is subsequently unfolded again. This is disadvantageous for the user because
usually it is required to use the buggy for the same use either a reclined sleeping
position or the cot position, say, for a continuous period during which the buggy
will be required to be folded and unfolded a number of times. This may typically happen
when the buggy is used to take a child somewhere in a car and the child is asleep
in the inclined position, and it is desirable to transfer the sleeping child back
to the buggy in the reclined or cot position. There is a considerable advantage in
this feature of the invention in that the buggy can effectively be a pram for the
first period of a baby's life of 6 to 9 months during which the buggy will also unfold
as a pram after folding. This saves the user considerable time compared to existing
buggies which would have to be inclined each time they are unfolded. When the child
is older than 9 months and able to sit up the buggy can be converted to a push chair
and it will always return to a push chair mode after folding. Thus the buggy of the
present invention really does perform as a dual purpose cot and push chair as well
as separate pram and push chair in this way which has not been achieved previously.
1. A foldable baby buggy with an adjustable seat, including seat position setting means
(Fig. 6) settable to store the chosen seat position and to thereafter return the seat
to that position when the buggy is unfolded.
2. A buggy according to claim 1, wherein the seat position setting means comprises a
disc (50A) mounted for independent rotation on a hinge (33) between two bars (25,
31), with means (51, 52) for locking the position of the disc relative to one bar
(25) and means (60) for limiting the rotation of the other bar (31) relative to the
disc.
3. A buggy according to either previous claim wherein the seat comprises a seat back
settable to a range of positions between relatively upright and fully reclined and
hinged to a seat base (26) arranged to slide forward substantially horizontally as
the seat back moves to the reclined position.
4. A buggy according to claim 3 wherein a first point (29) on the seat back and partway
thereup is coupled to the frame of the buggy by coupling means (28) so as to move
vertically, a second point (33) on the seat back partway between the first point and
the bottom edge thereof is coupled to the frame by a hinged bar (31) so as to move
diagonally forward and downward, and the seat base is slidably mounted (at 24) on
the frame to move horizontally.
5. A buggy according to claim 4 wherein the hinged bar (31) extends upward beyond the
back of the seat to form an X linkage therewith, an upper horizontal bar (35) is hinged
to the top end (34) of that bar, and a vertical link bar (36) is hinged between the
forward ends of the upper horizontal bar (35) and the base of the seat (26).
6. A buggy according to claim 5, wherein the coupling means (28) comprises a bar extending
rearward from the back of the seat and a further horizontal bar (39) is provided,
hinged at one end (38) to the forward end of the upper horizontal bar and sliding
at its back end (40) on the further horizontal bar.
7. A foldable baby buggy substantially as herein described and illustrated.
8. Any novel and inventive feature or combination of features specifically disclosed
herein within the meaning of Article 4H of the International Convention (Paris Convention).